Muffler attachment for telephones.



G. KRACKER.

MUFFLER ATTACHMENT FOR TELEPHONBS.

APPLICATION FILED JAN. 18, 1912.

1,064,492, Patented June 10, 1913.

WITNESSES INVENTOR UNITED STATES PATENT onnion- GEORGE KBACKER, 0F PHILADELPHIA, PENNSYLVANIA.

imrnnnn ATTACHMENT FOR Tnnnrnouns.

Application filed January 18, 1912. Serial No. 671,954.

To all whom it may concern:

Be it known that LGEORGE Know, a citizen of the United States, residing in the city and county of Philadelphia, State of Pennsylvania, have invented a new and useful Mufiier Attachmentfor Telephones, of which the following is a specification.

This invention relates to a muffler for use in connection with telephone. transmitters and has for an object to provide a device wherein the sound waves may be transmitted in the usual manner to the telephone transmitter without interference and whereby the mufiiing medium is interposed between said sound waves and the exterior of the device. By this construction it becomes possible to use a telephone in the ordinary manner and -transmit. the sound as usual while the voice of'the user is 09mpletely muffled to the exterior of the device and the words cannot be distinguished by anyone in the vicinity thereof. This action is of course predicated upon the position of the user, since it is necessary in operation to have the mouth positioned well within the mouthpiece of the attachment so that sound vibrations may not escape to the exterior thereof. V

The device is an improvement on my Patout No. 901,108, granted October 13th, 1908,

and in operation is far superiorand eflectiv'e. Furthermore-a new result is produced since the novel construction of my present invention does not destroy the voice timbre and-it is therefore possible torecognize the voice of any one who is employing the attachment as readily as without the said attachment.

It further consists of other novel features of construction, all as will be hereinafter fully set forth.

For the purpose of illustrating my invention, I have shown in the accompanying drawing one form thereof'which is. at present preferred by me, since the same has been found in practice to give satisfactory and reliable .results, although it is .to he understood that the various instrumentalities of which my invention consists can be variousl arranged and organized and that my invention is not limited to the precise arrangement and organization of these instrumentalities as hereiushown and described:

Figure 1 re resents a vertical section through a mu er embodying my invention. Fig. 2 represents a perspective of the casing of the device. Fig. 3 represents .a section of the sound muflling spiral.- Fig. 4 represents 3. pers ct-ive of the retaining ring for the mufihng spiral. Fig. 5 represents a perspective of the end cap of the casing and its adjuncts- Similar numerals of correspondingparts in the figures.

Referring to 'the'drawings, 1 designates a casing preferably cylindrical and having secured thereto a mouthpiece 2 which is in communication with the interior of the easing and formed, in the present instance, with a beaded edge 3 in order to provide a smooth contact surface to closely fit against the face of the user of the device. This mouthpiece 2, as here shown, is fixedly secured to the casing 1' by means of the inturned crimped edge 4. y

5 designatesa muffling member preferably in the lform of a spiral, the side edges of which are each provided with a flange 6 which forms spacing elements between the several convolutions of the spiral in order to form a continuous passageway 7 from the interior of the casing 1 to a point adjacent exhaust openings 8-formed in the wall of the said casing. As here shown, this mufliing member or spiral is .held in place by means of an annulus 9 .or retaining reference indicate collar, the o ning 10 of which" is preferably arrange in alineme'nt with the mouthpiece 2, while the outer edges of the said annulus are inwardly turned as shown at 11 and are adapted to be pressed into position between the outer convolutions of the spiral member and the casing 1, thereby firmly holding the parts in position.

12 designates a. cap provided with a circumferential beaded flange 13 slotted at suitable intervals as shown at 14, in order to permit engagement with suitable projections 15 of the casin 1, whereby the parts are secured together y a common type ofbayonet joint, although it will of course be understood that any suitable fastening means may be employed for this purpose and it will further'be understood that the diameter of this beaded cap 13- is sufliciently large to permit the necessary telescoping action with the casing 1. This cap; 12 is provided with a central opening 16 alined with the opening 10 and the mouthpiece 2 and is also provided with outwardly extending flanges 17, the edge of which is rever'sely turned to form a shoulder 18 over which is seated an 7 ordinary telephone.

annular strip of rubber 19 or like flexible material by means of which the device is removably secured to the mouthpiece of an In the present instance, this rubber member 19 is held in place through the. medium of a collar 20,

likewise of elastic material, which is adapted to be forced over the shoulder or round" ed edge 18 and snaps into'pos'ition as shown in. Fig. 1, thereby preventing displacement of the attaching means and yet allowing '7 ready removal of the same or substitution of over a portion of the telephone transmitter another piece of the same material in case of wear. 7

In operation the device is placed in position upon the mouthpiece of a telephone and there held by stretching the. member 19 in which position all of the openings be tween the transmitting device and the mouthpiece 2 are in alinement to transmit sound waves directly to the said transmitter The user of the device by placingthe mouth closely .withinjthe mouthpiece 2 may talk into the telephone in the ordinary manner and whatever sound waves escape to the exterior thereof are obliged to travel a circuitous path through the spiral member 5 and finally discharge through the openings 8 at which time they are so weakened as to prevent any words being distinguished.

It willnow' be apparent that l have provided a simple and effective mufiing device for use in connection with telephone transmitters wherein a continuous sound mufiling spiral member is utilized to deaden' and decrease the sound waves prior to their discharge to the exterior of the casin and -'wherein the sound waves which are adapted to'contact with the transmitting mechanism are not intercepted or affected by any interiposed parts. It willalso be noted that in a device of th1s character it is very necessary -within the muflling device and rendering it impossible to recognize the voiceof the speaker. It has been found in practice that in mufliers of the spiral type such as shown in my prior patent, No. 901,108, of October,

13th, 1908, that owing to the dimensions of the spiral way, whichmust necessarily be small to form a compact article, that dust mittenmen 192 and dirt enterf'this way or path and within in the manner heretofore described, and it.

is with this in view that I have devised a separable or sectional structure which permits ready access tethe spiral channel to allow the dirt to be removed and the article again become an efficient muflling device. In my present constructio-n'I have obviated suchv difiiculties and the sound waves from one word or tone are so quickly distributed through the broad channel of the. convolutions of my mufiling spiral that the next word or tone is not interfered with and therefore the voice timbre is'not destroyed.

It will now be apparent that l have devised a novel and useful construction of a muffler attachment for telephones which embodies the features of advantage enumerated as desirable in the'statement of the invent-ion and the above description and while I have, in the present instance, shown and described a preferred embodiment thereof which has been found in practice to give satisfactory and reliable results, it is to be understood that the same'is susceptible of modification in various particulars witlr out departing from the spirit or scope of the invention or sacrificing any of its advantages.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

Ina device of the character stated, a casing tubular in form and having an open end affording free access to the interior thereof, a mouthpiece secured to the opposite end of said casing and communicating with the interior thereof, a sound mufiiing spiral member located in said casing and readily removable therefrom, said member being circumferentially arranged with respect to the axial path of sound waves from said mouthpiece, an annular member fitted within the open end of said casing and retaining said spiral member in normal position, a cap having an opening therein adapt ed to fit over the open end of saulcasmg.

lugs on said casing, means on said cap adapted to 1nterlock with said lugs to removably secure said cap to said casing, an outwardly flaring flange formed integral with said.

cap, and an elastic fastening means secured to said flange and adapted to retain said casing in position upon a telephone trans:

- GEORGE KRACKER.

- Witnesses: f-

' Ronnn'r M. Benn, C. D. MCVAY. 

